The present invention relates to a method and system for collecting and handling polluted oil products and petrol and oil tanks.
In many instances, it may happen that the contents of tanks such as, for example, oil storage tanks may accidentally or otherwise become polluted. Consequently, care must be taken when the tank is emptied by the sewage truck, which truck subsequently delivers the contents of the tank to a treatment plant.
While it is possible to a certain extent to separate the impurities from the oil and usefully recycle the same into a pure oil product at a treatment plant, a considerable amount of unnecessary work has already been carried out prior to reaching the treatment plant by virtue of the transportation of the entire contents of the tank to the treatment plant.
The aim underlying the present invention essentially resides in providing a method and system for collecting and handling polluted oil products whereby it is possible to decide at the tank location whether the liquid drawn from a storage tank is immediately reuseable since most pollutants such as, for example, water, introduced into an oil product, are revealed by a stratification of the tank contents whereby, during a suctioning operation wherein the contents of the storage tank are drawn therefrom, it is possible to ascertain whether the suctioned material consists of a useful liquid or a polluted liquid. Thus, rather than simply collect all of the liquid in the sewage tank, it is thus possible in accordance with the present invention, during an actual suctioning operation to observe the nature of the suctioned product and thereby to selectively lead the suctioned liquid to a tank for polluted liquid and/or a tank for non-polluted liquid, respectively. Upon suctioning or pumping up all liquid from the tank, the usable liquid portion can be immediately returned to the tank and only the polluted portion of the liquid can be transported to the treatment plant.
Often a polluted portion of the liquid represents a relatively small quantity of the suctioned liquid, so that the total transport capacity necessary for the polluted portion of the liquid can be drastically reduced by, for example, postponing the transportation to distant treatment plants until only the decidedly polluted liquid has been accumulated from a number of locations in a given region
Additionally, by virtue of the features of the present invention, the user of a tank system, the contents of which may have been exposed to pollution, realizes a significant advantage in that the tank contents are not completely removed since the reuseable portion of the liquid can be returned to the tank immediately upon an isolation of the polluted liquid from the sewage tank.
The aim underlying the present invention essentially resides in providing a method and system for handling polluted products such as oil products, whereby it is possible at the inception of the suctioning or drawing operation of the tank contents to distinguish between pure and polluted liquid and thus obtain a pure portion of the liquid for immediate reuse; whereas, only the actually polluted liquid portion is accumulated for transportation to a regional treatment plant.
In accordance with the present invention, a mobile sewage unit is provided which includes, for example, a sewage tank and a working tank, and, during a suctioning or drawing operation, the suctioned or drawn product is examined and fed to the sewage tank of the mobile sewage unit as long as the suctioned or drawn product is polluted and to a working tank when the product is pure, whereupon, the pure product is returned from the working tank to the emptied tank and the separated portion of the product in the sewage tank is transported to the treatment plant. Thus, it is possible in accordance with the present invention to more economically carry out a reclaiming or recycling of a usable portion of the liquid product.
In order to carry out the method of the present invention, a sewage vehicle is provided with an extra working tank and one or more transportation tanks for transporting pure products. A variety of jobs normally associated with the sewage handling such as, for example, tank flushing can more conveniently be carried out than in prior art arrangements, as will be apparent from the following description, when the mobile sewage system includes a suction and transfer pumping gear arrangement.